Stoke's captain Ryan Shawcross has committed his future to the club, agreeing a five-and-a-half-year contract to stay at the Britannia Stadium.

The 25-year-old central-defender has been one of Stoke's biggest assets in their four-and-a-half seasons in the Premier League and the manager, Tony Pulis, was desperate to tie him to a new deal after he was called up by England for the recent friendly with Sweden.

The contract is reported to be worth £13.5m and is the biggest in the club's history, making Shawcross the club's top earner with Peter Crouch on £45,000 a week.

Pulis, who signed Shawcross from Manchester United in January 2008 for £1m, after he had completed a successful loan spell, said: "It's fantastic for us as a football club. We're really, really pleased to have him. He's been the bedrock of what we've been trying to do over the past five or six years and we're really pleased that he's finally agreed."

The two parties have been in talks for a number of weeks, with Shawcross indicating he was ready to sign a long-term deal in November.

Shawcross brought his family to the club's Clayton Wood training ground on Thursday for the signing of the contract, and the defender's three-year-old son, Freddie, accompanied Pulis to the press conference.

The manager said: "It's a long contract, Ryan has to get it right, the football club has to get it right, and they've managed to come to an agreement, which is great news for everybody. I think the world of Ryan. I think he's a great lad. We've just seen little Freddie in here. They're a great family and they're part of this football club.

"We've signed Asmir [Begovic], we've signed Marc Wilson and now Ryan. Steven Nzonzi's on a long-term contract, so that's four top young players. And that's what we want to do – keep improving it, keep getting younger players and players who will grow together at the football club.

"We're not going to do what Manchester City have done, we're not going to do a Chelsea, we have to build gradually and steadily, and that's what we've done over the last five years. We'll do it our way, in our fashion. A lot of people don't like it, but who cares."